Studies will continue on the synthesis of beta-lactams which contain structural units analogous to the penicillins and cephalosporins. Particular attention will be directed toward the synthesis of monocyclic beta-lactams such as 3-aminonocardicinic acid and other monocyclic systems which have shown antibiotic activity. The experimental procedures will utilize newer methods for the formation of beta-lactams involving oxidative decarboxylation and decarbonylation of azetidine carboxylic acids and esters. Other potential routes to penicillins involve transformations of the readily available addition products of pencillamine with the mucohalic acids.